GC stops working after collecting a chunk of memory

[最萌 小汐 <sumneko@...>]

```lua

collectgarbage('generational', 10, 50)

debug.sethook(function () end, 'c')

print(_VERSION)

print(collectgarbage('count'))

local t = {}

for i = 1, 100000 do

    t[i] = (' '):rep(5000) .. tostring(i)

end

print(collectgarbage('count'))

t = nil

collectgarbage()

collectgarbage()

print(collectgarbage('count'))

local t = {}

for i = 1, 1000 do

    t[i] = (' '):rep(100000) .. tostring(i)

    t[i] = nil

    if i % 100 == 0 then

        print(collectgarbage('count'))

    end

end

```

Run this code, prints:

```

Lua 5.4

22.7333984375

595727.66894531

84.794921875

19628.545898438

39172.432617188

58716.319335938

78260.206054688

97804.092773438

117347.97949219

136891.86621094

156435.75292969

175979.63964844

195523.52832031

```

Seems GC stops working.

But if I set parameters for `collectgarbage` to default (`20, 100`, makes it more negative), it works fine.

This line `debug.sethook(function () end, 'c')` is not necessary. If you remove this line, you need to set the GC parameters to `10, 20` to reproduce this problem.

-- sumneko